Conventionally, there has been known a technology in which infrared light is emitted to a face, reflected light of the emitted infrared light is detected to be outputted as an infrared light image, and face recognition is performed by use of the infrared light image.
In the above technology, power consumption due to emission of infrared light is not particularly taken into consideration. Thus, in a case where the above technology is applied to, for example, a hand-held information terminal that operates on a battery, there is room for improvement in terms of battery consumption used for emission of infrared light.
Therefore, an object of the present exemplary embodiments is to provide an information processing apparatus, an information processing system, a computer-readable non-transitory storage medium having stored therein the information processing program, and an information processing method, which are capable of reducing power consumption due to emission of infrared light.
In order to attain the above object, the following configuration examples are conceivable, for example.
One example of the configuration example is an information processing apparatus including an infrared light emitter capable of emitting infrared light and a camera capable of at least taking an infrared light image, the information processing apparatus configured to: control emission of the infrared light; repeatedly obtain an image taken by use of the camera; repeatedly execute a face detection process based on the obtained image, the face detection process being for detecting the face of a user; perform first control of, when face detection has been successful with the infrared light emitted, stopping emission of the infrared light, and of causing, in the face detection, the face detection process to be executed with the emission stopped; and perform second control of, when face detection has been successful with emission of the infrared light stopped, causing, in the face detection, the face detection process to be continued with emission of the infrared light stopped, and when face detection has been failure with emission of the infrared light stopped, causing the infrared light to be emitted and causing, in the face detection, the face detection process to be continued.
According to the above configuration example, when it is not necessary to emit infrared light, the infrared light is stopped, and thus, power consumption of the information processing apparatus can be reduced.
As another configuration example, in the first control, when the number of successes of face detection has become greater than or equal to a predetermined number, emission of the infrared light may be stopped.
According to the above configuration example, while accuracy of face detection can be maintained, power consumption of the information processing apparatus can be reduced.
As another configuration example, in the first control, when a change in relative positional relationship between the user and the camera is smaller than a predetermined threshold, emission of the infrared light may be stopped. Further, the information processing apparatus may be further configured to detect a motion of the information processing apparatus itself, and in the first control, based on a magnitude of the detected motion of the information processing apparatus itself, it may be determined whether the change in the relative positional relationship is smaller than the predetermined threshold. Further, in the first control, based on a change in a position of the face viewed from the camera based on a detection result in the face detection, it may be determined whether the change in the relative positional relationship is smaller than the predetermined threshold.
According to the above configuration example, when the positional relationship between the user and the information processing apparatus (camera) is stable, emission of the infrared light can be stopped. Thus, while accuracy of face detection is maintained, power consumption of the information processing apparatus can be more effectively reduced.
As another configuration example, in a case where, in the second control, the infrared light has been caused to be emitted and the face detection has been caused to continue the face detection process, emission of the infrared light may be stopped again when face detection is successful, and the face detection process with the emission stopped may be caused to be executed, in the first control.
According to the above configuration example, power consumption of the information processing apparatus can be more effectively reduced.
As another configuration example, in the first control, a time interval from when the infrared light has been caused to be emitted to when emission of the infrared light is stopped again in the second control may be gradually increased.
According to the above configuration example, while accuracy of face detection is maintained, power consumption can be reduced.
As another configuration example, the information processing apparatus may be a hand-held information processing apparatus.
According to the above configuration example, in such a case where while a hand-held information processing apparatus is being used, the held information processing apparatus is carried from, for example, a dark place to a light place, power consumption of the hand-held information processing apparatus can be reduced, and at the same time, convenience by the face detection process can be maintained.
As another configuration example, the information processing apparatus may be an information processing apparatus operable on a battery.
According to the above configuration example, consumption of the battery can be reduced, and convenience of the information processing apparatus can be enhanced.
According to the present embodiment, power consumption due to emission of infrared light can be reduced.